Weighing machine



Jan. 8, 1952 G. A. OLOFSSON ETAL WEIGHING MACHINE Filed Aug. 11, 1947INVENTORS GUSTAV A. OLOFSSON By LOYDE N. CHUBB ATTORNEYS Patented Jan.8, 1952 WEIGHING MACHINE Gustav A. Olofsson and Loyde N. Chubb, Lansing,

Mich., assignors to Olofsson Tool & Die Company, Lansing, Mich., 'acorporation of Michigan Application August 11, 1947, Serial No. 767,944

17 Claims. 1

The present invention relates to a machine for weighing predeterminedamounts of bulk material.

It is an object of the present invention to provide a weighing machineof the type described in which the material to be weighed is depositeddirectly onto the platform of a weighing scale.

It is a further object of the present invention to provide a weighingmachine including a weighing scale which receives the bulk materialdirectly and which supports no part of the material supporting structurewith the exception of a light scraper blade.

It is a further object of the present invention to provide a weighingmachine including means for depositing material on a platform of a scaleat a controlled rate, for discontinuing deposit of material when apredetermined weight has been attained, and for thereafter scraping thematerial off the scale at an independently controllable rate.

' It is a feature of the present invention to provide in combinationwith a weighing scale, a pair of laterally movable, interconnectedopenbottom buckets which are located above and out of contact withthe'scale so as to support bulk material on the scale and to scrape aweighed amount of bulk material from the scale.

' Other objects and features of the invention will become apparent asthe description proceeds,

especially when considered in conjunction with the accompanyingdrawings, wherein:

Figure 1 is a fragmentary side elevation, partly in section, of theimproved weighing machine;

Figure 2 is a detail view of the pointer actuated switch mechanism;

Figure 3 is a fragmentary enlarged section on the line 3-3 of Figure 1;and

Figure 4 is a simplified wiring diagram of the mechanism.

' Referring now to the drawings, there is indicated a weighing scale lhaving a flat horizontal platform I l and including an adjustablecounterbalancing weight I2 by means of which the scale may be set tomeasure predetermined weights of bulk' material.

Surrounding the scale I0 is a hopper 20 which includes a housingstructure 2! for enclosing the scale so as to prevent entry of foreignmatter therein. The lower portion of the hopper 20 is open as'indicatedat 22 and may be connected to a spout of suitable design to effectdischarge of weighed quantities of bulk material into containers.

Located above the plane of the platform I l are a pair of buckets 30,these buckets being formed of sheet material and each beingsubstantially rectangular in cross section. The adjacent walls 3! of thebuckets are spaced apart, spacers 32 being provided for this purpose.The two buckets are united together by a light angle piece 33 and by abar 34 which surrounds the two buckets and is associated with a lightpiece of sheet metal 35, as indicated in the figures. A supportingframe, indicated generally at 40, is provided and includes posts 4|between which are supported a pair of guide bars or rails 42. Suitablemeans such as bushings embracing the guide bars 42 are provided on thebucket assembly, one such being diagrammatically indicated at 43. Thisarrangement provides for independent support of the bucket structure sothat neither of the buckets 30 in operation come into contact with theplatform ll of the scale.

The buckets are open at their top as indicated at 36, and are open attheir bottom as indicated at 31. In addition, the inner walls 3| of thebuckets 30 terminate as indicated at 38 at a point above the bottomedges of the remaining walls of the buckets.

Loosely received in the space between the walls 3| is a scraper blade50, which may conveniently be formed of a light metal, such for exampleas aluminum. The thickness of the blade is substantially less than thespace between the plates 3l so that as the buckets 30 are movedtransversely to the right and left as seen in Figure 1, the blade 50inclines accordingly. This rocking movement or shifting of the blade 50serves to prevent lodging of the bulk material being weighed in thespace between the walls 3|.

Means are provided for effecting lateral movement of the buckets 30 tothe right and left as seen in Figure 1. In the position illustrated inthe drawing, the left-hand bucket 38 is'in position to receive bulkmaterial, and the other limiting position of the bucket assembly isreached when the right-hand bucket 30 is over the scale platform IIoccupying the illustrated position of the left-hand bucket 30.

The means for effecting lateral movement of the buckets 33 comprises amotor means which is herein illustrated as a hydraulic cylinder 89containing a piston to which is connected a piston rod 6| secured to athreaded boss 62 on the bucketassembly. A suitable source of hydraulicfluid is provided and is connected by lines 63 to an adjustable meteringvalve 64 which connects to lines 65 and 6B for supplying fluid underpres- 3 sure to the cylinder 60 at a rate controlled by the valve 64.

Mounted on the supporting structure id is a vibrating feed trough Iwhich includes a solenoid H. The feed trough If! is of standard typepurchased on the open market an the details of its construction form nopart of the present: invention. It may be said,.however, that the deviceoperates by high frequency actuation of the solenoid H causing movementof the trough it in one direction accompanied by a slow .return of thetrough due to the spring mounting of the structure. This device is.adjustable-so as to control the rate of depositzof bulkmate rialtherefrom. Illustrated-at in Figure lie the discharge opening of anelevator, by means of which bulk material is fed into thetrough- 1i andthe elevator is will normally be provided with means for controlling itsspeed/so as to regulate the rate of deposit of the bulk material intothe vibrating trough it.

Mounted on the frame Jiii) :are :a pair ofposts 80 carrying limitswitches Bid and iiib including actuators 82 in position to be engagedby the appropriate one'of the buckets 39.

The weighing mechanism may alsobeof'standard type and includes a.movable pointer 85 which movesover a graduated scale in known manner.In order that the weighing device or scale may control the operation ofthe weighing machine without imposing a load on the weighing platformII, a magnetic switch indicated in Figure 2-is provided. Conveniently,this switch may include a permanent magnet 86 carried by the pointeri85and *a-switch device l-which includes a movable elementmoved intocircuit closing relationship when the magnet 86 is brought intoproximity -to the switch.

The platform ltmay, if desired, 'be provided with a light angle iron 90(see vlF'igureBirserving to close off the space between-the bottomaoithe buckets 3! and the-upper 'surfacepf the platform of the scale.However, these angle pieces Bil are out Of contact with the side walls:of the buckets 3B and constitute a negligibleloadcon the platform .11.

It will be observedthat movement of therscraper blade 50 as a result oflateral 'movementof the buckets 30 across the upperrsurfa'ce ofthe'platform II results in a tipping of the blade'fiilinto a'position inwhich its side surface contacts the lower edgeof the bucket wall 3! .ofthe bucket which is in position to bewfilled. nFurther, the inclinationof the scraper blade :55! :duringlateral movement of the :buckets 30-:provides -a most efiicient scraping action across the :upperusurface ofthe platform I 4 since a sharp lower corner of the scraper blade 59,will'thereby be brought into contact with the surfaceoftheplatform.

Since the only *movable element which :engages the platform all is therelatively light scraper'blade 50, a veryefficient weighing action isobtained. Compensation is made for the weight'of the scraper blade 50and no other compensation need beregarded. Accordingly, a very accurateweighing of bulkmaterial deposited on the platform! I is obtained, and:the buckets 3G may be modified or replaced without the necessity ofcompensating for any changes in their weight.

The magnetic switchs'i is connected to a suitable'relay actuating acontrol valve in the hydraulic system so as to effect lateral movementof the-buckets 39 immediately upon attainment of a predetermined weightas determined by discharge from the elevator 15 into the trough l!) is.01" course controlled in accordance with the average rate of passage ofmaterial through the weighing machine proper.

connected :to :the ,relay system actuating the hydraulicipiston:cylinderand serve when actu- Limit switches 8! are ated to set up suitablecontrol circuits for efiect- -ing. ..rev.erse lateral movement of thebuckets upon'the next closure of the magnetic switch 8'2. As best seenin Figure 4, a suitable electric circuit for controlling the mechanismto attain the functions .described'above :is illustrated .in simplified,form. According to this :figure limit switches am and 81b are eachconnected in seriessacross .the line with control relays .90 and .92respectively. Switch 87 is "connected across the line in series with :acontrol relay 9%. The relay 9!} controls normally open contacts 90a and65b; Control relay 92 controls normally open contacts 92a and92b.Control relayed controls normally closed contact 9411 and normally opencontacts 9% and 940. contacts 90a and-92a are connected in-parallel'andtogether are in series with the solenoidll of the vibratory .feeddevice, and normally closed contact 94a is also inseries withthe'solenoid ii. Contactsfiilb andiltbarezinseries with one solenoid 93associated with the reversing valve 98 which controls 'thedirectionof-fiowofi fiuid through hydraulic .lines .65 and 66. 1Contacts 92b and e icare in'series with the-other solenoid Hit of thevalve 98.

. The :operation .-.of :the mechanism :is believed apparent-from theforegoing but-willbebriefly reviewed. Assume that 'oneof the limitswitches, as-for example 81a, is closed and that solenoid ii isenergized so that bulk'material ,is-being fed into one of the buckets.

At this time limit switch 811) and the switchafll controlledby'thepointer of the weighing mechanism are open. Since control :relay93 is*energized, normally open contact 90a is closed and a circuit iscompleted through the vibrator solenoid Tl through the normally closedcontact 94a. At this time normally open contact :90!) is closed but thecircuit to the-solenoid silsis open at contacts 94?). Upon attainmentofa-xpredetermined weight of material on the platformthe switch 8? closesenergizing relay-allwandithus immediately opening normally closedcontact 9 11 which instantly terminates operation of the vibratory feedmechanism; At the sameitime normally open contacts 9 th and Me areclosed. Since normallyopen contact' flb wasclosed under the conditionsassumed, a current iscompleted through solenoid 96 thus reversing thevalve 98. The eifect of this is to cause the buckets to traverse fromone limiting position to the other. Asthistraverse starts -limitswitchilia opens," thus de-energizing solenoid -96 and opening contacts 90::and 901). Opening of contact 8% does not affect the reversing valvesincethe valve has been shifted toreverse position previou ly. Duringtraverseof the buckets from one position to the other switch 8? opens,permittingnormally closed-switch .Ma 'to sclose.

However, at this time contacts 90a and 92a both remain open since bothlimit switches are open. At the same time, opening of switch 81 openscontacts 84b and 940 which is without immediate effect. When the bucketsreach the other limiting position limit switch 3 lb is closed, thusenergizing controlrelay 92. This results in closing normally opencontact 92a which completes a circuit through the vibrator solenoid Hand normally closed contact 94a thus initiating the feeding cycle. t thesame time contact 92b closed, thus completing a circuit to open contact940. This latter contact will be closed when switch 8? is closed whichconcludes a cycle.

,The use of the metering valve 84 in the hydraulic system is ofconsiderable importance in the present machine. It will ordinarily beset to effect a relatively rapid traverse of the buckets 30 so as toquickly discharge the weighed material from the platform II, at whichtime it falls into the hopper 20 and is discharged through the spoutconnected to the bottom opening ZZtherein. However, in the event that arelatively dense material, such for example as sugar or rice, has beenweighed on the platform II it is desirable to effect a slower lateralmovement of the buckets so as'jto obtain a gradual discharge of theweighed material from the hopper 20. Otherwise a too rapid discharge ofheavy bulk material might under some conditions, such for example asdischarge of the material into paper bags, be highly undesirable.

The vibrating trough is provided with adjustable means for effectingvibration thereof so as to control the rate of discharge of bulkmaterial therefrom into the appropriate one of the buckets 30. By ajudicious selection of the rate of feeding effected by the trough I0 andthe rate of lateral movement effected by the hydraulic cylinder 60,maximum output may be obtained without at the same time leading toundesirable dumping of heavy masses of weighed material, as previouslydescribed.

The present machine is adaptable for weighing substantially any type ofdry bulk material, such for example as potato chips, sugar, driedvegetables such as rice, beans or the like, dried fruit, chemicals, andin fact any material capable of being handled by the vibrating trough Hiand being contained by the open-bottomed ing different commodities. suchfor example as mixed seed. In such :case a plurality of elevators may beemployed, each of which elevates a particular type of seed and depositsinto the vibrating trough. The portions of the ingredients of the finalmixture may be controlled, as is obvious, by varying the rate of speedof the elevators.

While the open-bottomed buckets illustrated and described above haveproved to be perfectly satisfactory for all materials, it is within thepurview of the present invention that these buckets be formed withdownwardly and outwardly flaring walls if such construction is foundnecessary due to the nature of the materials being weighed.

The drawings and the foregoing specification constitute a description ofthe improved weighing machine in such full, clear, concise and exactterms as to enable any person skilled in the 6 art to practice theinvention, the scope of which is indicated by the appended claims.

What we claim as our invention is:

1. A machine for weighing and discharging batches of bulk materialcomprising a weighing platform, an open bottomed bucket, support meansindependent of said weighing platform for supporting said bucket withits lower edge spaced slightly above said platform for sliding movementbetween a weighing position directly over said platform and a dischargeposition at one side of said platform, feed means directly above saidplatform for discharging bulk material into said bucket and onto saidplatform when said bucket is in weighing position, power means forshifting said bucket between weighing and discharge positions, andcontrol means responsive to a predetermined weight of bulk material onsaid platform to terminate operation of said feeding means and to causesaid power means to shift said bucket from weighing position.

2. A machine as defined in claim 1 in which the side walls of saidbucket are vertical so that the entire weight of bulk material Withinsaid bucket is supported by said platform. 7

3. A machine as defined in claim 1 comprising in addition a lightscraper blade loosely carried by said bucket and movable across the topof said platform upon shifting of said bucket.

4. A machine as defined in claim 1 comprising in addition adjustablespeed control means for said power means to selectively control the rateof discharge of bulk material.

5. A machine for weighing and discharging batches of bulk materialcomprising a weighing platform, a pair of interconnected open bottomedbuckets, support means independent of said weighing platform forsupporting said buckets with their lower edges spaced slightly abovesaid platform for lateral sliding movement between a first position inwhich one of said buckets is in weighing position directly above saidplatform and the other bucket is in a discharge position at one side ofsaid platform, and a second position in which said one bucket is indischarge position and said other bucket is in weighing position, feedmeans directly above said platform for discharging bulk material intothe bucket in weighing position over said platform, power means forshifting said buckets between said first and second position, andcontrol means responsive to a predetermined weight of bulk material onsaid platform to terminate operation of said feeding means and to causesaid power means to shift said buckets from one position to the other.

6. A machine as defined in claim 5 in which the side walls of saidbuckets are vertical so that the entire Weight of the bulk materialwithin the bucket over the platform is supported by said platform.

7. A machine as defined in claim 5 in which said buckets areinjuxtaposition and have a flat, common inner wall, the direction ofshifting movement of said buckets by said power means being generallyperpendicular to said wall.

8. A machine as defined in claim '7 in which said common inner wall isdouble and provides an interior space, and a scraper blade looselymounted'in the space and movable across the top of said platform uponshifting of said buckets.

9. A machine as defined in claim 8, said blade being of less thicknessthan the width of said space, :whereby said; :blade is inclined andpresents a bottomcorner as it is scrapedacross said platform.

'10.A machine as defined in claim 5, comprising in addition. adjustable7 speed Scontrol means for? said power means-to selectively control therateeof discharge of bulk material.

11. A machine as defined in claim 5 in which saidfeed means is avibratory troughe effective when de-energized to stop feed of bulkmaterial substantially instantaneously.

,12. A machine as defined in claim 5 in-which said power means is'ahydraulic piston and cylinder device.

13. A machine as defined in claim 5 in which said support meanscomprises pair of spaced parallel. rails, and means onsaid bucketsslidable on said rails.

,14. A machine as defined inclaim 5 comprising in addition anindicating/pointer movable by I pointer 1* carries {a magnet movable51in; yaw-path adjacentsaid'switch.

16. A machine as definedin claim :14 iin-;which said control meansvcomprises in additiona-pair of limit switches actuated by, said :bucketsat either limit of. shifting movement thereof.

17. A machine as defined claimrlfi comprising .in addition meansoperable by. closure of either limit a switch'to initiate operationof;;-said feed means.

,GUSTAV A. OLOFSSON. LOYDE N. CHUBB.

REFERENCES CITED The following references are of record in the 'file ofthis "patent:

UNITED STATES, 'IPA'I'ENTS Number Name Date 441,302 HarmlessNOV.-25,j-1890 683,304 Lemon Sept.; -24, 1901 -70 6,442. 1 McLeod et a1.V Aug.;5,; 1902 1,321,726 Ellis 1 Nov. 11,; 1919 42,033,586 Noble Mar.10 11-936 FOREIGN PATENT-S Number Country Date .364,942 GermanySept..11,.19'20

